Eravacycline

Eravacycline is a fluorocycline given intravenously for complicated intra-abdominal infection, with activity against MRSA, vancomycin-resistant enterococci, ESBL and carbapenem-resistant Enterobacterales and Acinetobacter. It does not work against Pseudomonas and failed in urinary infection.

Classification. Fluorocycline (synthetic tetracycline).

Mechanism. Binds the 30S ribosomal subunit and overcomes efflux and ribosomal protection resistance; bacteriostatic.

Spectrum. MRSA, streptococci, vancomycin-resistant enterococci, ESBL Enterobacterales, carbapenem-resistant Enterobacterales, Acinetobacter baumannii, Stenotrophomonas and anaerobes. Not active against Pseudomonas aeruginosa or Burkholderia.

Pharmacokinetics. IV only. Half-life about 20 hours. Protein binding 79 to 90%. Eliminated mainly through bile and faeces, with low urinary concentrations.

Reserve agent; availability in East Africa is very limited. No loading dose.

Adults. - Complicated intra-abdominal infection: 1 mg/kg IV over 60 minutes every 12 hours for 4 to 14 days. - Co-administration with a strong CYP3A inducer (for example rifampicin): 1.5 mg/kg every 12 hours. - Not for complicated urinary tract infection or bacteraemia as monotherapy.

Children. Not established.

Alternatives. Tigecycline, omadacycline, ceftazidime avibactam, meropenem, colistin-based regimens.

Contraindications. Hypersensitivity to eravacycline or tetracyclines; pregnancy.

Adverse effects. Infusion-site reactions, nausea, vomiting, diarrhoea, raised liver enzymes. Serious: anaphylaxis, pancreatitis, Clostridioides difficile infection, tooth discolouration, hepatotoxicity, photosensitivity.

Interactions. Strong CYP3A inducers lower exposure (increase dose); strong CYP3A inhibitors raise exposure; warfarin (INR rise).

Common prescribing errors. Using it for urinary infection or Pseudomonas infection and omitting the dose increase with rifampicin.

Special groups. - Pregnancy: avoid (foetal tooth and bone effects). Breastfeeding: avoid. - Older adults: usual dose. - Kidney impairment: no adjustment. - Liver impairment: Child-Pugh A no change; Child-Pugh B or C 1 mg/kg every 12 hours on day 1, then 1 mg/kg every 24 hours.

Preparation. Reconstitute each 50 mg vial with 5 mL sterile water or 0.9% sodium chloride, then dilute in 0.9% sodium chloride to 0.3 to 0.6 mg/mL and infuse over 60 minutes. Store vials at 2 to 8 degrees Celsius.

Baseline and monitoring. - Baseline: weight, liver tests, pregnancy test, medication review. - During treatment: liver tests twice weekly; lipase if abdominal pain.

Stop rules. Stop for anaphylaxis, pancreatitis or severe hepatotoxicity.

Referral and escalation. Infectious diseases consultation is needed before use.